Abstract This article presents OO-HMethod, an extension of the OOMethod conceptual modelling approach to address the particulars associated with the design of web interfaces. It is based on the OO-Method class diagram, which captures the statics of the system. The design of the interface appearance and the navigation paths are driven by the user navigation requirements. To achieve its goal, OO-HMethod adds several navigation and interface constructs to the OO-Method conceptual model, which define the semantics suitable for capturing the specific functionality of web application interfaces. A new kind of diagram, the ’Navigation Access Diagram’ (NAD) is introduced. All the concepts represented in the NAD are stored in a repository, and from there a functional interface is generated in an automated way. One of the main contributions of this paper is not the proposal of yet another method for web modelling but the extension of an existing conceptual modelling approach.